A056670 Largest prime factor of which the exponent exceeds 1 among prime factors of central binomial coefficient, C(n, floor(n/2)); largest non-unitary prime factor of A001405(n); or the maximal prime divisor of the largest square divisor(A056057(n)) of C(n, floor(n/2)).

1, 1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 2, 2, 2, 3, 3, 1, 2, 1, 2, 2, 2, 1, 2, 5, 5, 5, 5, 3, 3, 3, 3, 3, 3, 5, 5, 5, 5, 3, 3, 2, 2, 2, 2, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 2, 2, 2, 2, 2, 2, 2, 2, 7, 7, 7, 7, 7, 7, 3, 3, 1, 2, 2, 2, 5, 5, 7, 7, 7, 7, 7, 7, 3, 3, 5, 5, 5, 5, 3, 3, 7, 7, 7, 7, 7, 7, 5, 5, 3, 3, 3, 3, 3, 3, 3

Offset

1,6

Links

Table of n, a(n) for n=1..105.

Example

n=28: binomial(28,14) = 2*2*2*3*3*3*5*5*17*19*23, so a(28)=5;
n=342: C(342,171)=32*F, where F is squarefree, so a(341)=2.

Crossrefs

Cf. A001405, A056057, A056175.

Sequence in context: A329322 A067924 A344912 * A170925 A030189 A275678

Adjacent sequences: A056667 A056668 A056669 * A056671 A056672 A056673

Keyword

nonn

Author

Labos Elemer, Aug 10 2000

Status

approved